Visitors to Toronto City Hall should have to walk through metal detectors, surrender bags for inspection, and watch their councillors from behind glass walls, according to a secret city staff report to councillors.

The proposed transformation of what is now a bustling, mostly open building — home to a wedding chapel and daycare as well as official meeting space and wickets for parking passes and more — is in a confidential report compiled with threat assessments from Toronto police and Public Safety Canada.

Some councillors are vowing to fight the proposed clampdown, calling it an affront to democracy and open government. Others say the dark realities of 2017 require heightened measures like those imposed by Edmonton. One told the Star councillors are “sitting ducks” ripe for attack.

The report warns that city hall, with its famous curved towers, and Nathan Phillips Square outside it, are a “target for serious threats” so change is required to protect the site from “lone wolf terrorists, organized terror groups, and other individuals with grievances.”

“An attack on city hall is not only an attack on a government building, it is an attack on a symbol of Toronto, Canada, as well as an attack on a place that many people have or will visit,” city staff warn Tory and all 44 councillors who will have final say over any changes.

Currently, security officers watch over city hall’s front doors but the visitors who stream in most days are free to roam the atrium and offices that serve the public. Since a Parliament Hill attacker killed Cpl. Nathan Cirillo in 2014, additional contracted security officers have watched over secondary doors now restricted to city staff and others with access passes.

People who watch committee meetings are not screened. Those entering the city council chamber must only open their bags for inspection.

Possible changes include:

Walk-through metal detectors at the front doors. If a security officer can’t determine the cause of an alarm, they would screen the visitor with a hand-held wand. Councillors and city staff would only need to present access passes in a special lane.

Bags carried by visitors would be put on a table for physical inspection, rather than undergo X-ray “due to the large flow of people.”

In the council chamber the waist-high glass wall that now separates the public gallery from councillors’ seats should be made up to 30 centimetres taller, with an “angled top guard” to help repel an attacker, and extended around the sides now protected by velvet rope.

Two committee rooms with no barriers should get waist-high glass walls between public seats and those for council members and city staff. The walls would give people extra time to react in case of an attack.

The recommended changes would cost $774,000 a year for extra security plus another $500,000 in one-time capital costs.

On Tuesday, after release of a public portion of the report that referred only to “patron screening,” Councillor Gord Perks vowed to fight any change.

“They’re not patrons, they’re citizens and this is their palace,” Perks (Ward 14 Parkdale—High Park) told the Star.

“The accessibility of city hall should be the same as the accessibility of the sidewalk.”

Councillor Paula Fletcher also said city hall must remain open, noting a host of offices serving the public unlike Queen’s Park and Parliament Hill.

But some colleagues feel vulnerable in city hall and say beefed-up security won’t stop harmless visitors from enjoying the building.

“We’re sitting ducks,” said Councillor Jim Karygiannis, who was a Liberal MP until shortly before the Parliament Hill attack.

“I cannot forget what happen at Parliament,” the Ward 39 Scarborough-Agincourt councillor wrote in an email, adding he recently had to report to security a city council visitor who showed him a “switchblade” knife “within feet of the backs of city councillors.

“City hall is the first target on terrorists’ minds after Parliament (and) Queens Park.”

Paul Ainslie, the councillor who chairs government management committee, supports the introduction of metal detectors and glass walls.

“I think we do need an enhanced level of security and what’s being proposed isn’t that different from what people experience at rock concerts or sporting events,” said Ainslie (Ward 43 Scarborough East). “I think members of the public, even if they are slowed down for a couple of minutes, would feel safer too.”

Here are security measures at some other city halls:

Edmonton last year introduced metal detectors and bag searches for people attending committee and council meetings, as well as a glass partition between visitors and councillors.

Montreal has police search visitors on city council days.

Ottawa has no metal detectors or bag screening but says enhanced security “may be considered in the future.”

Calgary has, since 2015, made visitors to the council chamber pass through a metal detector and submit bags and purses to a search.

Winnipeg requires visitors to city hall to sign in and wear identification badges at all times.